1. Field
Exemplary embodiments relate to a radio frequency (RF) trap, a superconducting magnet apparatus including the same, and a magnetic resonance imaging (MRI) apparatus, and more particularly, to an RF trap in which load impedance is finely optimized, a superconducting magnet apparatus including the same, and a magnetic resonance imaging apparatus.
2. Description of the Related Art
An RF trap is used to remove a common mode current occurring due to induction of the current of a transmission source on an electric cable, for example, on an RF transmission (Tx) line. The RF trap is attached to an outer conductor of an RF transmission line for power-feeding of the transmit RF coil of, for example, a magnetic resonance imaging (MRI) apparatus and is used to remove a current induced on the outer conductor of the transmission line which affects the performance of the MRI apparatus.
A related art RF trap is attached to the RF power-feeding transmission line of the MRI transmit RF coil and includes a fine-optimization unit for generating a load impedance value suitable for a relevant frequency to enable cylindrical inner/outer conductors that perform shielding to prevent RF signals of a transmitter from being induced on a power-feeding line and the RF trap to effectively remove and attenuate RF radiation signal sources.
In the related art RF trap structure, optimization for load impedance is made by a combination of capacitance value and a structure that is attached between an outer conductor and an inner conductor of an electromagnetic wave shield and the load impedance is generated at a relevant frequency. However, the related art method is problematic because the attached structure and shape of the inner and/or outer conductor have to be redesigned in each instance and/or many capacitor elements have to be combined and attached for load impedance optimization, and optimization for finer load impedance according to the relevant frequency is difficult to fine-tune and implement.